Freelance tax in Thailand — a plain-English guide
Foreign freelancers invoice Thai corporate clients, who withhold 3% tax at source on the fee and issue a Section 50 Bis withholding certificate (50 ทวิ) as proof. For example, a ฿30,000 fee has ฿900 withheld, so you receive ฿29,100 directly via PromptPay (Thailand's instant transfer system). You keep each certificate to credit that prepaid tax on your annual personal return. Payments skip BillsOS entirely — the QR code embeds your bank account, and clients scan to pay you directly, with no per-transaction fee and no custody of your funds. Withholding applies when the amount meets the ฿1,000 threshold and the payer is a juristic person (company). BillsOS issues bilingual Thai/English invoices formatted per the Revenue Department. This is general information, not tax advice.
How to invoice a Thai client, get paid by PromptPay, and handle the 3% withholding tax and the 50 Tawi — explained in plain English for foreign freelancers.
By the BillsOS team · Updated 8 Jun 2026
1) Invoicing a Thai client
Your invoice should carry your and the client’s name and address, tax IDs where applicable, the line items, the amount, and a document number/date. Thai corporate clients often want a bilingual invoice and will use it to process payment in their accounting system.
2) The 3% withholding tax and the 50 Tawi
When your fee meets the threshold, a Thai corporate client must withhold 3% of your (pre-VAT) fee, transfer the remainder to you, and issue a 50 Tawi certifying it remitted that tax in your name.
| Fee (before VAT) | ฿30,000.00 |
| Total invoiced | ฿30,000.00 |
| Less withholding tax 3% | -฿900.00 |
| Net the client pays (QR amount) | ฿29,100.00 |
The direction that matters: On your sales invoice YOU are the payee. The client withholds and issues the 50 Tawi to you — you neither withhold nor issue it. Your job is to keep every 50 Tawi you receive.
3) Getting paid by PromptPay
PromptPay is the instant transfer system Thai clients use daily. Generate a QR with the exact amount, the client scans and pays straight into your account — no intermediary. BillsOS builds the QR offline into your own account, never sees the funds, and charges no per-transaction fee.
Why foreign freelancers pick BillsOS
- Bilingual Thai/English documents — readable by your Thai client and by you
- Revenue-Department-correct formatting with the withholding/VAT computed correctly
- No custody of your money and no fee — funds land in your own PromptPay account
How many days in Thailand makes me a tax resident?
A common situation for foreign freelancers: working remotely from Thailand for more than half the year, billing both Thai and overseas clients. The general rule is that spending 180 days or more in Thailand within the same calendar year makes you a Thai tax resident, which affects whether certain foreign-sourced income you remit into Thailand also gets counted for tax. Income from Thai clients is withheld and reportable regardless of how many days you spend in the country.
Tax-residency and foreign-sourced-income rules have details that can change and get complicated depending on your situation. This is general background, not advice for your specific case — check your own status with the Revenue Department or an international tax specialist.
Tools & guides
- Withholding tax & VAT calculator
- Is my withheld tax creditable or refundable?
- PromptPay QR generator
- Withholding tax rates · Thai tax answers
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BillsOS only formats and computes documents for you. This is general information, not tax advice — please confirm with the Revenue Department or your accountant.